Exposure apparatus and method

Abstract

An exposure apparatus for transferring a pattern on a mask onto a photosensitized substrate by exposure, having an illumination optical system, a mask stage for moving the mask and a substrate stage for moving the substrate. An attenuator is disposed between the light source and the photosensitized substrate for attenuating the illumination beam with a variable attenuator rate. A controller controls the output power of the light source and attenuator of the illumination beam such that the exposure energy approaches a predetermined desired value. A stage controller controls the velocities at which the mask stage and the substrate stage are moved for scanning according to the difference between the exposure energy measured by the sensing system and the predetermined desired value.

What is claimed is: 
     
       1. An exposure apparatus which illuminates a mask with an illumination beam from a light source through a condensing optical system and exposes a photosensitive substrate with the illumination beam through the mask, comprising: a first optical integrator disposed between said light source and said condensing optical system;   a second optical integrator disposed between said first optical integrator and said condensing optical system;   a first adjustment device disposed between said light source and said condensing optical system to adjust at least one of the extent and the shape of a region through which said illumination beam passes at an exit side of said second optical integrator;   a second adjustment device disposed between said light source and said second optical integrator to adjust the extent of an illumination field on an entrance surface of said second optical integrator; and   said second optical integrator comprising a first group of lens elements defining the entrance side of said second optical integrator and a second group of lens elements defining the exit side of said second optical integrator, each of said first group of lens elements and each of said second group of lens elements having different cross-sectional shapes from one another.   
     
     
       2. An apparatus according to claim 1, further comprising a field stop disposed between said second optical integrator and said condensing optical system to define an illumination area on said mask illuminated with said illumination beam, wherein each cross-sectional shape of said first group of lens elements is substantially similar to the shape of said illumination area.   
     
     
       3. An apparatus according to claim 2, further comprising: a stage system by which said mask is moved in synchronization with said photosensitized substrate so that said photosensitized substrate is exposed with said illumination beam,   said field stop defining said illumination area which has a slit-like shape.   
     
     
       4. An apparatus according to claim 1, wherein a size of each of said second group of lens elements is determined to substantially include a plurality of images of said light source formed by said first optical integrator.   
     
     
       5. An apparatus according to claim 1, wherein said first adjustment mechanism has a plurality of field stops which have a size and a shape at least one of which is different from one another and one field stop selected from said plurality of field stops is disposed to be close to an exit surface of said second optical integrator.   
     
     
       6. An apparatus according to claim 1, wherein said second adjustment mechanism has a plurality of lens elements having different powers and one lens element selected from said plurality of lens elements is disposed between said first optical integrator and said second optical integrator.   
     
     
       7. An apparatus according to claim 1, further comprising a drive system which is connected to said second optical integrator so that said first and second lens elements groups are moved relative to one another. 
     
     
       8. An apparatus according to claim 1, further comprising a third adjustment mechanism which is disposed between said light source and said second optical integrator so that a quantity of light of said illumination beam which enters said second optical integrator is adjusted. 
     
     
       9. An apparatus according to claim 8, wherein said third adjustment mechanism includes a field stop which is disposed between said first optical integrator and said second optical integrator.